Fig. 15

Although only low-volume Gleason score 3 + 3 = 6 was again noted at repeat TRUS biopsy (Fig. 13), a follow-up MP-MRI was performed 3 months later because of interval doubling of PSA to re-evaluate for a focus of higher grade cancer. Axial T2W TSE image (a) demonstrates that the small low T2 SI focus in the left PZ has grown substantially (open white arrow) with bulging and nodular extension into the peri-prostatic fat (arrowhead), which was reported as representing extra-prostatic extension. The lesion again demonstrates restricted diffusion; note increased SI on trace b1000 mm²/s EPI and low SI on ADC (white arrows in b and c, respectively) and demonstrated an aggressive type III contrast curve on DCE (d). In the interval, a malignant-appearing lymph node developed along the left pelvic sidewall (e). Based on these findings a diagnosis of high-grade tumour with extra-prostatic extension and metastatic adenopathy was provided. The patient underwent RP based on the imaging findings, he declined a repeat biopsy because of previous urosepsis related to prior TRUS biopsy. Corresponding microscopic images (f and g) demonstrate Gleason pattern 4 tumour (white arrows in f) and extra-prostatic extension of tumour (open arrow), which is beyond the prostate capsule (black line) and into the peri-prostatic fat (g)